The present invention is directed to overcoming problems associated with the coiling of heavy-duty cables, particularly electrical power cables used in lighting, audio, rigging, and power generation industries.
The way electrical cables have traditionally been coiled is to use reel-to-reel spoolers. However, a common problem with reel-to-reel spooled cables is that they become tangled when they are unwound, which can be very time consuming and labor intensive to untangle. Reel-to-reel spooling causes tangling because it is based on the traditional method of “straight coiling.”
Straight coiling is the practice of coiling a cable in the same direction coil after coil. This causes the cable to be twisted because straight coiling goes against the natural twist in the cable. That is, every cable has an inherent natural twist. When a cable is straight coiled in the same direction, the cable is turned against its natural twist. As a result, straight coiling can cause the cable to twist internally, creating stress in the cable and damaging it.
It is better to coil with the natural twist in the cable and not against it. The over-under coiling method preserves the natural twist in the cable. Over-under coiling refers to a method of twisting the cable in one direction to make a first loop, and un-twisting it to make the next loop, and repeating this alternation until all the cable is neatly coiled. (This is also called “flip-coiling,” due to the nature of flipping the cable back and forth.) The basic principle is that the first loop twists the cable, and the next loop untwists it.
There are a number of important advantages to the over-under coiling method. First, the method eliminates twists and tangles in the cable by allowing the cable to coil according to its natural state, thus preventing damage and prolonging the lifespan of the cable. Second, by eliminating twists and tangles in the cable, the over-under coiling method allows the cable to lie flat, which facilitates storage. A cable that is looped in the same direction as in straight coiling will not lie flat and will not stack properly. This makes the cable much more cumbersome to store and transport. When a cable is coiled using the over-under method, it can be stored compactly without damaging its internal components.
Third, a cable that is coiled using the over-under method can be easily uncoiled because there is no twist and tangle, which makes for easier and faster work. An over-under coiled cable can be quickly unwound in the field by either throwing the coil outward or just pulling on one end. In fact, when well coiled, a 100-foot (30 m) cable can be thrown across an area and land in a straight line, without tangles. In short, the over-under coiling method improves the lifespan, storage capacity, and uncoiling speed of the cable.
However, the difficulty with the over-under coiling method is that heretofore the only way to do it was by hand. However, flip coiling by hand can be very time consuming and labor intensive given the size and weight of heavy-duty electric cables. For example, the entertainment production industry uses various sizes and lengths of heavy-duty electrical power cable to deliver and distribute power from electrical panels or generators to control and power lighting fixtures, audio systems and rigging motors. The heaviest power feeder cable “4/O” is 1 inch in diameter (about 2.5 centimeters) and weighs approximately 1 pound per foot (about 0.7 kilograms per meter). An average cable 100 feet long (30 meters) will weigh approximately 100 pounds (45 kilograms). The accepted industry standard is to coil heavy-duty electrical power cables in 20-inch diameter (about 0.5 meters) coiled bundles. This diameter size makes the coiled bundle easier to store, transport, and handle.
The industry state of the art of coiling heavy-duty electrical power cables and uses conventional cable reel coiler machines to re-coil cable onto a spool. According to industry standards, the desired dimension for a coil bundle is 20 inches (0.5 meters) in diameter for ease in lifting, transportation and storage. Though over-under coiling can be done by hand, it is very time consuming and is very labor intensive to coil a 100 ft/100 lbs cable (30 m/45 kg).
Twisted coiling machines do exist in the prior art but are not designed to handle the type of heavy-duty cables used for electrical power or high-tech audio equipment, such as the one described in U.S. Pat. No. 7,690,544 to Zaruba, incorporated by reference in its entirety herein. Other coilers such as those described in U.S. Pat. No. 4,513,922 to Dufour, U.S. Patent Application Pub. No. 20080230643 to Ornskar and PCT Application Pub. No. WO2013180665 to Span, also describe different coiling machines, each hereby incorporated by reference in its entirety. However, these other coiling devices not suitable for rapid easy coiling of heavy-duty electrical cable.
Therefore, there remains a need to improve coiling devices that can coil heavy-duty cables to minimize tangling, improve coiling time, and vary the size of the coiled cable. One skilled in the art will recognize many other benefits of this new coiling device and method over apparatus and methods used to coil cables.